Similar open-source project https://github.com/DataCovey/nornweave

Inbox-as-a-Service for AI Agents Open-source, self-hosted API that turns standard email providers into intelligent, stateful email for LLMs via REST or MCP.

There is also this project for using email as a coordination layer between agents for multi-agent workflow.

https://github.com/Dicklesworthstone/mcp_agent_mail

Intresting